Melting and holding furnace



Dec. 2, l941. .1. w. BROWN MELTING AND HOLDIN FURNACE Filed Sept. 15,1934 4 Sheets-Sheet l INVENTOR.

9 1. J. w. BROWN 2,264,740

MELTING AND HOLDING FURNACE Filed se t. 15, 1934 4 Sheets- Sheet s JbHNW5EOWN I NVENTOR.

ATTORNEY.

vii- .0 i I syfidjwmgw Dec. 2, 1941. w ROWN 2,264,740

MELTING AND HOLDING FURNACE- Filed Sept. 15, 1934 4 Sheets-Sheet 4INVENTOR. JbHN W 520 WN ATTORNEY.

Patented Dec. 2, 1941 UNITED STATES PATENT' OFFICE 2,264,740 MELTING ANDHOLDING FURNACE John w. Brown, Cleveland, 01116 Application September15, 1934, Serial No. 744,254

27 Claims.

This invention relates to improvements iii melting and holding furnaces,that is to say furnaces for melting non-ferrous metals and holding suchmelted metal in the molten state and at the desired temperature forcasting purposes.

One of the objects of the invention is the provision of means inconnection witha furnace similar to that disclosed in my copendingapplication Serial No. 577,182, filed November 25, 1931, now Patent No.2,020,101 issued Nov. 5, 1935, for controlling the temperature of themetal in the ladling pit to a considerable extent without varying thatin the heating chamber, whereby the formation of castings of variouskinds is facilitated, and whereby a plurality of ladling pits may beemployed, and the flow of heat to them from the heating chamber may bere u lated in such a way as to provide molten metal at differenttemperatures for different ladling pits, such a condition being highlydesirable in order to secure castings of best quality when the characterof the castings or the method of forming them varies.

Another object is to provide an improved furnace of the type mentionedsuch that the metal in the heating chamber and'in the ladling pit may bemaintained molten at a minimum cost overnight, or for other idleperiods.

Another object is the provision of means permitting rapid heating of thefeeding chamber and the ladling pit, as well as the heating chamber,after a. shut-down or idle period.

Still another object is the provision of means in the heating chamberfor causing the flame and hot gases of combustion to circulate directlyabove the molten metal to a greater extent than heretofore in order toconserve heat and render the furnace more eilicient, with less damage tothe roof and less heat loss through the roof.

Another object of the invention is the provision of a feeding chamber,for scrap metal particularly, so arranged as to make use of the heat ofthe exhaust gases from the heating chamber of the furnace.

Another object is the provision of means for controlling the amount ofheated gases passing into this feeding chamber in order to avoid burningor oxidation of the metal and in order to bring about melting of themetal at the desired rate during periods of furnace operation.

Another object is the provision of means for readily and easily removingbits of iron and the like released from the scrap. as it is melted.

A further object is the provision of means for burning the vapors risingfrom a new batch of scrap in which there ismore or less oil and grease,and thereby utilizing the same as fuel while preventing smoke nuisance.

Other objects and features of novelty will appear as I proceed with thedescription of those embodiments of the invention which, for thepurposes of the present'application, I have illustrated in theaccompanying drawings, in which Fig. 1 is a longitudinal verticalsectional view of a furnace embodying the invention.

Fig.2 is a horizontal sectional view of the.

same taken substantially on the line 2-2 of Fig. 1.

Fig. 3 is a fragmental vertical sectional view through the delivery endof the furnace, showing a gooseneck in position in the ladling pit.

Fig. 4 is a side view of a further modification in which means isprovided for tilting the furnace in order to pour the contents of thesame.

Fig. 5 is a detail plan view of an operating mechanism.

Fig. 6 is a fragmental view corresponding to one end of Fig. 1, butshowing the scrap pan in an elevated position, and showing also adifferent position of one of the adjustable doors between the chambers.v

Fig. 7 is a view similar to Fig. 2 but on a smaller scale and showingthe feeding chamber arranged at right angles to the ladling pits.

Fig. 8 is a large scale fragmental sectional view of a portion of thefurnace wall in which a polished metal reflecting surface is employedfor heat insulating purposes.

' Fig. 9 is a transverse vertical sectionalview of the furnace showing acourse of replaceable lining blocks at or about the level of the moltenmetal where freezing and adherence of the metal to the furnace wallprincipally occurs.

Fig. 10 is an elevational view of a sliding door or partition.

Figs. 11 and 12 are detail vertical sectional views taken substantiallyon the lines ll-H an |2--l2 of Fig. 1, respectively.

In the drawings, the furnace has been shown as provided with an. outermetallic casing I0 and a lining ll of refractory material, with heatinsulating material l2 of suitable character interposed between thecasing and lining. Two transverse walls l3 and M of refractory materialare provided, forming the front and rear walls, respectively, of thecombustion and heating chamber IS. The front wall l3 and the rear walll4 both terminate well above the level of the molten metal in thefurnace. as indicated clearly in Fig.

1 of the drawings. The rear wall preferably rests upon and is supportedby a central pier or metal may be dipped or otherwise removed forcasting purposes. In the preferred form of the invention this part ofthe furnace is divided by a central longitudinal wall I! into twoladling pits I8 and I9. It will be apparent, however, that a single pitor a number of pits greater than two could be employed if desired. Whilethe compartments I8 and I9 are primarily ladlin pits, they sometimesreceive metal. For instance some material, such as defective castings,hot from the molds, is often put back in the ladling pits.

The rear end of the furnace beyond the wall l4 constitutes the feedingchamber'20. The bottom of this chamber is inclined downwardly andinwardly as disclosed in Fig. l, and at approxithe heating chamber I Iprovide a transverse dam 2|, the function of which is'to catch and holdferrous or other solid foreign material released from the melting scrapand sliding down the inclined bottom surface of the feeding chamber.

side walls thereof, at least as high as the maximum level of the moltenmetal, are covered with refractory and are heat insulated. The top 2|and the rear wall 22 of the chamber may also be heat insulated ifdesired, but are herein shown as constructed merely of sheet metal.

The rear wall 22 is provided with a large opening 23 through which scrapmetal may be fed into the chamber, a door 24 being provided to coverthis opening normally. 25 is a metallic apron attached to the outer wallof the furnace. Over this apron foreign material, dross and skimmingsmay be discharged when drawn over the rear end of the bottom of thechamber by a rake or a skimmer.

Above each of the ladling pits l8 and I9 r mount a hinged door 26 whichis of a size sufflcient to completely cover the opening above the pit.Each ladling pit is adapted to be cut of! to a greater or lesser extentfrom the combustion and heating chamber of the furnace by a slide orpartition 21 which consists preferably of a slab of rrefractorymaterial. This slide may be raised and lowered and held in any adjustedposition by suitable means, that illustrated consisting of a verticalrack 28 attached to the slide and a pinion 29 mounted for rotation uponthe furnace casing and adapted to be rotated by suitable means such as acrank (not shown). The slide 21 may be lowered to any desired extentinto the molten metal to thereby control the extent of communicationbetween the molten metal in the heating chamber and in the ladling pit.The slide may also be raised far enough to cause its lower edge to clearthe surface of the metal, thus providing a passage above the metal forcombustion gases and controlling the size of that passage.

In order to control the size of the opening l6 in-the rear wall [4 ofthe heating chamber, I provide a slide 30, a rack 3| and a pinion 32similar to the parts 211, 23 and 28 above described. I also provide aslide 33 with a rack 34 and a pinion 3%, this slide having ahorizontally Thebottom of the feeding chamber and the mately the pointwhere it joins the bottom of elongated window 38 therein ofapproximately the same height as that part of the opening it which isabove the normal level of molten metal. The slide 30 by adjustment canbe used to regulate the extent of communication above the level ofmolten metal, or with that communication cut on entirely it can be usedto regulate the extent of communication below the level of molten metal.When the slide 30 is raised above the top of opening I8, slide 33 can beadjusted to regulate the extent of communication above the metal levelwhile interposing more or less obstruction to the flow of metal. Also,with the slide 33 in a given position, slide 30 may be caused to cut offmore or less of the opening I6 above the metal level. thereby obtainingconditions of communication between the two chambers which it would beimpossible to obtain with either slide alone. 31 is a guard or housingelement used to prevent scrap from getting into the slide ways for theslides 30 and 33.

In onewall of the combustion and heating chamber I form a bell shapedopening 38 through which flame may be introduced into the chamber. Ifgas is the fuel employed, it may be delivered through a pipe 39 to aburner 48, the necessary air to support combustion being conducted tothe burner through a pipe 4|. In the same wall in which the flameopening 38 is located, I provide a second opening 42 with an inclinedbottom 42' leading down to the level of the molten metal in the furnace.This opening is used both as a feed opening for ingot metal and as anexhaust opening for the combustion gases, and because of its location inthe same wall with the opening 38 the gases that are exhausted throughthe opening 42 are caused to circulate over a considerable part of thesurface of the metal in the heating chamber before they make the turnand find an exit through that opening. The opening 42 may be closed by aslab 43 of refractory material or other suitable door. By placing aningot 0n the bottom of the opening 42 the heat in the chamber graduallymelts the ingot and the melted metal flows down the inclined surface 42'into the mass in theheating chamber, without splatter, and hence withless oxidation. If the door 43 is left open to a greater or lesserextent at such times the hot exhaust gases flow over the ingot, causingit to melt more rapidly.

Extending. from the top of chamber 20 there is a flue 44 provided with adamper 45. Normally the greater part of the combustion gases aredischarged through this flue. When a new batch of scrap, upon whichthere is more or less grease and oil, is put into the feeding chamber,this oily material is vaporized by the heat of the combustion gases,forming a dense smoke which would be objectionable if carried offthrough the flue 44. In order to correct this smoke nuisance I haveprovided a pipe 46 branching from the flue 44 and leading to a blower41, from the outlet end of which extends a pipe 48, the lower end ofwhich registers with an opening 4811 through the furnace wall directlyabove opening 38. When the pipe 48 is not in use the opening 48a isclosed by a slide or other shut-off 48b.

A damper 49 is mounted in pipe 46. When a new batch of scrap is to beplaced in the feeding chamber 20 the damper 45 is closed, the damper 49opened, and the slide 482) retracted. The blower 41 is then started. Thevapors of oil are then drawn from the flue by the intake for blower 41and directed into the furnace above the flames from burner 40. The oilvapors are thereby ignited. In this manner therefore the smoke nuisanceis eliminated, and at the same time some benefit is realized from theuse of the vapor as fuel. When the oil is all driven off the damper 45may be opened, the damper 49 and slide 48b closed, and the blower llstopped.

In one Side wall of the furnace I may provide a tap hole 50 opposite aspout mounted on the casing, in order that the metal in the furnace maybe drawn off when the operation of the furnace is to be interrupted ordiscontinued for any reason.

Although it is not essential, I prefer to support the metal scrapintroduced into chamber 20 upon a perforate pan 52 which is adjustableup and down so as to keep the scrap all above the level of the moltenmetal or to submerge it partly, as may be considered best under varyingconditions. For this purpose the pan 52 may be mounted upon pivots 53supported by the furnace casing, and it may be held in the desiredpositions of adjustment; by slotted sectors 54. The scrap itself isdesignated in Fig. 6 by the reference character S. All large pieces ofiron or other foreign solids are retained in the pan 52, and when thenon-ferrous metals forming a given charge are all melted the pan 52 maybe tilted to such an extent as to discharge the foreign materialbackwardly out -of the furnace. Upon withdrawal of the pivots 53, thepan 52 may be removed.

In Fig. 3 I have shown a gooseneck 55, such as is used in connectionwith die casting machines, it being positioned in a ladling pit of myfurnace. In this instance the pit is provided with a special cover 56having an opening 5'! through which the air line 58 to the gooseneckextends and an opening 59 through which the spout 50 of the gooseneckextends. This cover is also provided with an opening 6| through whichcombustion gases flowing into the pit from the chamber l5 may bedischarged. By raising the-slide 21 above the level of the metal, asindicated in Fig. 3, this exit for the gases is provided, and they arecaused to flow over the upper portions of the gooseneck keeping thelatter at such a temperature as to prevent the chilling of metal in thegooseneck or. the freezing of metal onto the inner walls of thegooseneck. The gooseneck may also be used as a mechanical ladling devicefor purposes other than die casting, for example in pouring permanentmold or sand castings, or ladling out the metal into ingot molds. Inthese cases the gooseneck acts as a pump for the molten metal.

Fig. 4 illustrates a modification of the invention wherein provision ismade for pouring the contents of the furnace rapidly when occasionarises to do so. Toothed rockers 62 are secured to the sides of thefurnace casing and engage perforated flanges 63 on supporting rails 64.The furnace casing forward of these rockers is of less width than thedistance between the rails 64, and at its forward extremity has apouring spout 65. Suitable means are provided for raising or loweringthe rear part of the casing. As shown herein this means may consist of anut 66 swiveled in a bracket 6'|.mounted on the flange 63 with a screw64 threadably mounted in the nut and extending through a bracket 68which is swiveled to the casing In. On either side, of bracket 68 thescrew 64 is provided with collars 69 and 70 which are pinned orotherwise fixed upon the screw. The smooth upper end of the screw 64carries a circular rack H which is fixed to the screw. An operatinghandle 72 turns upon the smooth upper end of the screw and carries areversible ratchet pawl 13 which is held in either of its two positionsof adjustment by a coil spring 14. When it is desired-to raise the rearend of the furnace the pawl I3 is thrown to one position, and when it isdesired to lower the casing the pawl is thrown to the opposite position.

As the furnace rises or rolls on its rockers 62 the nut 66 tilts and thebracket 68 swivels upon its mounting. When .the furnace is inpouringposition the various parts'of the operating mechanism occupy thepositions illustrated in dotted lines in Fig. 4.

Under some circumstances it may be disadvantageous to have the threechambers of the furnace arranged in line. Where it is consideredpreferable, I may arrange the ladling pits i8 and H! at right angles tothe feeding chamber 20, as shown in Fig. '7. By making the heatingchamber I5 square in horizontal dimensions I am enabled to make this"change in arrangement without any change in th proportions of the partsentering into the ladling pits and feeding chamber.

In Fig. 9 I have shown a belt of readily removable and replaceablematerial, preferably brick splits 15, which are supported by therefractory lining 16 of the furnace. This belt is positioned at thelevel of the molten metal, where adherence of metal to the furnace wallsoccurs principally. After a period of operation this ad-- remove thisbelt of extra refractory material 15 and replace it at relatively smallexpense and with a relatively short shut-down:

Preferably as a part of the heat insulation of a my furnace I employmetallic plates 18 forming a part of the furnace wall,. as illustratedin Fig. 8. These plates have highly polished inner surfaces for thepurpose of reflecting the heat waves. The preferred material is steel,plated with chromium, and polished.

The furnace herein described is, adapted for operation either with ingotmetal or scrap metal, or both. When scrap metal is used partially orwholly, the slides 30 and 33 are so adjusted as to deliver the properamount of hot gases to the feeding chamber to heat and melt the scraprapidly with a minimum of burning or oxidation. Of course the necessaryrapidity of the melting will. depend upon the rapidity of withdrawalfrom the ladling pits and the rate at which ingot metal is added to themass. In some cases communication between the heating chamber and thefeeding chamber may be mostly below the level of molten metal, it beingobvious that no oxidation of the scrap can occur if it is submergedwithin the molten metal.

Frequently scrap and ingot metal are com bined. In such case I usuallycause part of the combustion gases to pass out of the heating chamberthrough the opening l6 and part of .them through the opening 42, and byregulating the sizes of these openings the relative amounts of scrap andingot melted may be controlled to a considerable extent.

Generally during periods of operation when castings are being made theslides 21 will be extended downwardly into the molten metal to a greateror lesser extent, communication below the metal level being suflicientto maintain the metal in the ladling pits at the proper castingtemperature. The best temperature for casting will vary more or lesswith'the character of the castings being made. For instance castingshaving small delicate parts can be better made from a metal of arelatively high temperature, whereas the usual run of castings do notrequire such hot metal. By adjustment of the slides 21 to differentheights the temperature of the metal in the ladling pits can be changedconsiderably without any other change in furnace operation. The rate ofwithdrawal of the metal from the ladling pit also affects thetemperature of the metal therein. For instance, if large castings arebeing made and the rate of withdrawal is consequently rapid, the rate offlow of hot metal into the pit from the heating chamber is rapid and thetemperature in the pit therefore more closely approximates that in theheating chamber. Where two operators are working with metal drawn fromthe same furnace to produce two castings of different character, themetal in the two pitsl8 and I9. may be maintained atdifferent-temperatures by adjusting the slides 21 to different heights,and thus the single heating chamber may be caused to furnish metal atthe ideal temperatures for both jobs.

When it is desired to maintain a charge of metal in the furnace moltenduring a period of idleness, as for example over night, I close thedoors 24, 26 and 43, and raise the slides 21, 30 and 33 entirely out ofthe metal. The burner 40 is then turned down to reduce the size of theflame projected into the heating chamber, thereby conserving fuel. Thecombustion gases then divide, part of them passing through the openingsl6 and fiowingover the metal in the feeding chamber 20, and part of thempassing into the ladling pits-l8 and I9. At such times the doors 26 maybe closed completely, or may beopened slightly in order to create adraft. The metal in the feeding chamber and in the pits is therebymaintained molten.

I may also vary the extent of communication between the combustion andheating chamber on the one hand and the feeding chamber and ladling pitson the other hand by altering the height of the metal in the furnace.

Sometimes it is desirable to add considerable ingot metal at one time bydropping ingots into the ladling pits, and then to melt this metal andheat up the entire mass to casting temperature rapidly. To accomplishthis it is necessary merely to raise the slides 21, 30 and 33 to causethe combustion gases to flow over the surface of the metal in the pitsand in the feeding chamber, whereby the total surface of metal in thefurnace is greatly increased and the heating action correspondinglyaccelerated. During nor.-

mal operation it is usually desirable to have the slides 21 extend intothe molten metal, since the dross in the ladling pits cannot then passinto the heating chamber where it would act to insulate the metal moreor less against the heat of the flame in the chamber.

,When the slides 21, 30 and 33 are up, dross can'be skimmed from theentire surface of the metal in the furnace and drawn oif over the apron25, or out into the ladling-pits.

Having thus described my invention, I claim:

1. In a melting and holding furnace for nonferrous metals, a coveredheating chamber, a ladling pit adjacent to and communicating with saidheating chamber, and adjustable means for varying the extent of saidcommunication below the metal level.

2. In a melting and holding furnace for nonferrous metals, a coveredheating chamber, a ladling pit communicating with said heating chamberabove and below the metal level, means for opening or closing saidcommunication above the metal level, and a cover for said ladling pitmovable into or out of operative position.

3. In a melting and holding furnace for nonferrous metals, a coveredheating chamber, a ladling pit communicating with said heating chamberboth above and below the normal level of the molten metal in thefurnace, and adjustable means for varying the extent of communicationabove the level of the molten metal.

4. In a furnace of the class described, a covered heating chamber, aladling pit communicating with said heating chamber both above and belowthe normal level of the molten metal in the furnace, and a verticallysliding partition between said chamber and ladling pit adapted to 'belowered to cut off some or all of the said communication above the levelof the molten metal, and to be lowered into the metal to a variabledepth in order to cut off more or less of the said communication belowthe level of the molten metal.

5. In a melting and holding furnace for nonferrous metals, a coveredheating chamber, a plurality of ladling pits adjacent to andcommunicating directly with said heating chamber below the metal level,and adjustable means for varying the extent of the said communicationbetween the heating chamber and one of said ladling pits below the levelof the metal.

6. In a furnace of the class described, a covered heating chamber,aladling pit communicating with said heating chamber both above andbelow the normal level of the molten metal in the furnace, meansextending through a wall of the chamber for projecting flame into thechamber, one wall of the chamber having an exit opening for thecombustion gases above the normal level of the molten metal in thefurnace, and means for blocking of! some or all of said exit opening,whereby the combustion gases can be discharged either through the saidexit opening or through said ladling pit or divided between the exitopening and ladling pit in desired proportions.

7. In a melting andholding furnace for nonferrous metals, a heatingchamber, a feed ng chamber with an inclined base, said feed ng chamberbeing positioned adjacent the heating chamber and in communicationtherewith at its lower end, and a dam extending transversely of thefurnace near the junction point between the is provided in the feedingchamber as compared with the volume of molten metal in that chamber, andwhereby the raking of solid foreign material out of the feeding chamberis facilitated.

9. In a melting and holding furnace for nonferrous metals, a heatingchamber, a feeding chamber adjacent the heating chamber and incommunication therewith at its lower end, the bottom of the feedingchamber being inclined downwardly and inwardly to substantially thelevel of the bottom of the heating chamber, and a dam extending alongthejoint between the bottom of the feeding chamber and the bottom of theheating chamber below the normal common level of molten metal in the twochambers.

10. In a furnace of the character described, a heating chamber, afeeding chamber in communication with the heating chamber, means forvarying the extent of the communication between the heating chamber andfeeding chamber above the level of molten metal therein, and separatemeans for varying the extent of communication between the heatingchamber and feeding cham ber below the level of molten metal therein.

11. In a furnace ofthe character described, a heating chamber, a feedingchamber in communication with the heating chamber, and a perforate panfor holding scrap metal in said feeding chamber, said pan beingadjustable to any .one of a plurality of positions above or below thelevel of molten metal in the chamber.

12. In a furnace of the class described, a heating chamber, a coveredfeeding chamber adjacent thereto and in communication therewith gi"means for opening or closing and regulating'the extent of that part ofthe said communication which is above the level of molten metal in thefurnace, said feeding chamber havingfan opening for the reception ofmetal to bemelted, and a door for closing said opening.

13.'In a furnace of the character described, a heating chamber, a burnerfor fluid fuel arranged to project flame into said chamber, a feedingchamber in communication with said heating chamber above the level ofthe molten metal in the furnace, a flue for said feeding chamber, andcontrollable means for directing vapors and gases from said flue intosaid heating chamber adjacent said flame.

14. The method of, operating a melting and holding furnace fornon-ferrous metals wherein there is incorporated a closed heatingchamber and a ladling pit adjacent thereto with communication both aboveand below the normal level of metal, which method includesthe step ofvarying the extent of said communication for the purpose of controllingthe temperature 0 the metal in the ladling pit.

15. The method of operating a melting and holding furnace fornon-ferrous metals wherein there is incorporated a closed heatingchamber and a ladling pit adjacent thereto with commay be regulatedduring periods when metal is being withdrawn from, the ladling pit.

17. In a melting and holding furnace for nonferrous metals, 2. coveredheating chamber, a ladling pit communicating with said heating chamberbelow the normal level of the molten metal in the furnace, means forprojecting flame into the chamber, and means providing an exit oflimited extent from said chamber into said ladling pit above the levelof the molten metal in the furnace.

18. In a melting and holding furnace for nonferrous metals, a coveredheating chamber, a ladling pit communicating with said heating chamberboth above and below the normal level of the molten metal in thefurnace, and means for projecting flame into said chamber, whereby thecombustion gases may be discharged from the heating chamber intotheladling pit above the molten metal.

19. In a melting and'holding furnace for nonferrous metals, a coveredheating chamber, a ladling pit communicating with said heating chamberbelow the normal level of the molten metal in the furnace, and a feedingchamber communicating with the heating chamber both above and below thenormal level of molten metal in the furnace, whereby fresh metal may beadded in the feeding chamber and preheated and melted therein by wastegases-from the heating chamber, and whereby the effect upon thetemperature of the molten metal in the ladling pit of metal entering theheating chamber from the feeding chamber will be minimized.

.20. In a melting and holding furnace for nonferrous metals, a coveredheating chamber, a

munlcation both above and below the normal level of metal, whichincludes the step of varying the extent of communication above the saidlevel for the purpose of controlling the heating effect in the ladlingpit.

16. The method of operating a melting and holding furnace fornon-ferrous metals wherein there is incorporated a closed heatingchamber and a ladling pit adjacent thereto, which includes'the step ofvarying the extent of communication below the level of the metal,whereby the temperature of the metal in the ladling pit ladling pitcommunicating with one side of said heating chamber below the normallevel of the molten metal in the furnace, and a feeding chambercommunicating with the heating chamber both above and below'the metallevel at a point remote from the first named communication,whereby-fresh metal may be added in the feeding chamber and meltedtherein and whereby the effect upon the temperature of the metal in theladling pit of metal entering the heating chamber from the feedingchamber will be minimized.

21. In a melting and holding furnace for nonferrous metals, a coveredheating chamber, a feeding chamber in communication with the heatingchamber both above and below the normal level of the molten metal in thefurnace, and

a support in said feeding chamber adapted to hold solid metal above thesaid normal level of molten metal, whereby waste gases entering thefeeding chamber from the heating chamber may melt said solid metal andcause the melted metal to drop into the molten metal in the feedingchamber.

22. A metal melting furnace for non-ferrous metals having a meltingchamber with a metal charging opening in the side of said furnace andmeans for carrying a supply of metal to be melted duction of metal intothe furnace, means for supplying heat to said chamber, means forcontrolling the passage of gas through said flue, and an inclined chutedischarging into the stated furnace opening and adapted for holdingmaterials to be fed to the furnace in position where they are exposed tothe radiant heat generated in the melting chamber of the furnace.

24. A melting furnace for non-ferrous metals having a melting chamber,means for supplying heat to said chamber including a burner adapted toimpinge a flame against a wall of the melting chamber, said furnacehaving an opening located in a wall opposite to the first named wall ofthe melting chamber for the supplying of metal to the melting chamberand a damper controlled flue for the venting of heated gases from thefurnace, and means for supporting a supply of metal to be fed to thefurnace in a position adjacent to the stated opening so that such metalis subjected to radiant heat from the interior of the furnace.

25. A metal melting and holding furnace for non-ferrous metals having acovered heating chamber, a ladling pit communicating with said heatingchamber during normal operation below the metal level only, and afeeding chamber communicating with the heating chamber below the normallevel of molten metal, a barrier between the heating and feedingchambers at the normal metal level to prevent dross from passing andladling pit above the level of molten metal,

and means for raising said barrier to open up communication temporarilyabove the level of molten metal.

27. In a melting and holding furnace for non-' ferrous metals, a coveredheating chamber, a feeding chamber in communication with the heatingchamber below thenormal level of the molten metal in the furnace, andsupporting means in said feeding chamber adapted to hold solid metalabove the bottom of the feeding chamber, whereby the amount of solidmetal which can be immersed in the molten metal at any one time islimited, and the cooling of the molten metal by solid metal isproportionately limited.

JOHN W. BROWN.

